1. Field of the Invention
The invention relates to an inline vaporizer, and more particularly to an inline vaporizer disposed within a gas line for mixing a substance such as water into a carrier gas flow.
2. Related Art
Various types of systems have been developed for combining a gas such as air with a vaporized fluid for use in such applications as ventilator humidifiers, drug delivery systems (nebulizer), and combustion apparati creating fuel/gas vaporized mixture (stove burner, fuel injector).
Ventilator humidification systems have been developed to create a mixture of air and water vapor to provide a patient a more comfortable intake of oxygen through the soft tissues of the nose, mouth, and lungs, and to reduce or eliminate damage to the patient's lungs. These systems are an alternative to conventional ventilators and/or humidifiers that provide only dry air, which may damage the respiratory tissues.
As shown in FIG. 1, a conventional ventilator humidifier system 100 may include a ventilator 110, a first feed line 120, a second feed line 125, a water vessel 130, a heater 140, a second heater 145 for the second feed line 125 (such as a heated wire within the second feed line 125), and a return line 150. In the conventional ventilator humidifier system 100, a carrier gas such as air flows from the ventilator 110 through the first feed line 120. The first feed line 120 is connected to the water vessel 130 which contains water. Air in the feed line 120 passes through an open space at the top portion of the water vessel 130 that is not occupied by water.
The water vessel 130 is heated by an adjacent heater 140 to increase the amount of vapor in the water vessel 130. The heater 140 is typically located at the base of the water vessel 130 relatively near the ventilator 110 and outside of the first feed line 120. The heater 140 and the water vessel 130 may be positioned at a distance from the patient. The resulting vapor from the water vessel 130 combines with the air from the first feed line 120 to create a mixture of air and water vapor. The mixture of air and water vapor flows through the second feed line 125 to a patient. Air exhaled by the patient flows through the return line 150 to the ventilator 110.
When providing the mixture of air and water vapor to a patient, some of the water vapor in the second feed line 125 may condense before the mixture reaches the patient. This may occur because the distance between the water vessel 130 and the patient is relatively long and the ambient temperature of the second feed line 125 is generally cool relative to the temperature of the air and water vapor mixture. As a result, the condensed water vapor may collect in the second feed line 125 or return to the water vessel 130 for reheating.
To overcome this problem, a second heater 145 such as a heating coil may be provided within or along the second feed line 125 between the water vessel 130 and the patient. The second heater 145 provides extra heat to increase the temperature of the second feed line 125 and to maintain the water vapor form.
One of the disadvantages of the above-described conventional ventilator humidifier system 100 is that the addition of a second heater 145 along the second feed line 125 requires additional energy, which reduces the energy efficiency of the humidification process. Moreover, the heater 140 has to be turned on for a significant period of time in order to heat up the water in the water vessel 130 before starting air flow. This prolonged start-up time delays the operation of the system 100, and may require a health care provider to expend additional time when treating a patient. In addition, with this configuration, it is difficult to measure or adjust the amount of humidity in the system.
Further, the addition of a heating coil 145 along the second feed line 125 may complicate the operation of the system 100 and render it unwieldy because the bulky heating coil 145 must be positioned near the patient.
The heater 140 also poses a risk of injury, such as bums, because it is positioned outside the first feed line. The external positioning of the heater 140 with respect to the first feed line 120 also results in heat loss to ambient air, which reduces the overall efficiency of the conventional ventilator humidifier system 100.
These and other drawbacks may exist.